Method and apparatus for measuring flatness and/or relative angle between top and bottom surfaces of a chip

Abstract

A system and method for obtaining metrics of a semiconductor chip are provided. A first surface of a chip is positioned on a substantially flat receiving surface. A topography of the receiving surface is measured. A topography of a second surface of the chip is also measured. A relative angle between the receiving surface and the second surface of the chip are determined using the measurements of the receiving surface and the second surface of the chip.

1. A system for measuring a relative angle between surfaces of a semiconductor chip, comprising:
 a substantially flat receiving surface for receiving a first surface of a chip; and 
 a contour measuring device for measuring a surface topography of the receiving surface and of a second surface of the chip; 
 wherein the surface topographies of the receiving surface and the second surface of the chip are used to estimate the relative angle between the first and second surfaces of the chip. 
 
   
   
     2. A system as recited in  claim 1 , wherein the receiving surface is an optical flat. 
   
   
     3. A system as recited in  claim 1 , wherein the contour measuring device is an optical measuring device. 
   
   
     4. A system as recited in  claim 3 , wherein the optical measuring device is an interferometer. 
   
   
     5. A system as recited in  claim 1 , wherein the contour measuring device is a stylus-type device. 
   
   
     6. A system as recited in  claim 1 , wherein the chip is a tape head. 
   
   
     7. A system as recited in  claim 6 , wherein the second surface of the tape head is a substantially flat tape bearing surface. 
   
   
     8. A system as recited in  claim 1 , wherein the relative angle is measured to a factor of tenths of a degree. 
   
   
     9. A system as recited in  claim 1 , wherein the relative angle is measured to a factor of hundredths of a degree. 
   
   
     10. A system as recited in  claim 1 , wherein the relative angle is measured to a factor of thousandths of a degree. 
   
   
     11. A system as recited in  claim 1 , wherein multiple chips are positioned on the receiving surface. 
   
   
     12. A system as recited in  claim 1 , further comprising determining a flatness of the second surface of the chip. 
   
   
     13. A system for measuring a relative angle between surfaces of a semiconductor chip, comprising:
 an optical flat having a receiving surface for receiving a first surface of a chip; and 
 an optical interferometer for measuring a surface topography of the receiving surface and of a second surface of the chip; 
 wherein the surface topographies of the receiving surface and the second surface of the chip are used to estimate the relative angle between the first and second surfaces of the chip. 
 
   
   
     14. A system as recited in  claim 13 , wherein the chip is a tape head. 
   
   
     15. A system as recited in  claim 14 , wherein the second surface of the tape head is a substantially flat tape bearing surface. 
   
   
     16. A system as recited in  claim 13 , wherein the relative angle is measured to a factor of at least one of tenths, hundredths and thousandths of a degree. 
   
   
     17. A system as recited in  claim 13 , wherein multiple chips are positioned on the optical flat. 
   
   
     18. A system for measuring a relative angle between surfaces of a tape head, comprising:
 an optical flat having a receiving surface for receiving a first surface of a tape head, wherein the tape head has a substantially flat tape bearing surface; and 
 an optical interferometer for measuring a surface topography of the receiving surface and of a second surface of the chip; 
 wherein the surface topographies of the receiving surface and the second surface of the chip are used to estimate the relative angle between the first and second surfaces of the chip; 
 wherein the relative angle is measured to a factor of at least one of tenths, hundredths, and thousandths of a degree. 
 
   
   
     19. A system as recited in  claim 18 , wherein multiple heads are positioned on the optical flat. 
   
   
     20. A method for obtaining metrics of a semiconductor chip, comprising:
 positioning a first surface of a chip on a substantially flat receiving surface; 
 measuring a surface topography of the receiving surface; 
 measuring a surface topography of a second surface of the chip; and 
 determining a relative angle between the receiving surface and the second surface of the chip using the measurements of the receiving surface and the second surface of the chip. 
 
   
   
     21. A method as recited in  claim 20 , wherein the substantially flat surface is an optical flat. 
   
   
     22. A method as recited in  claim 20 , wherein the topographies are measured using an optical measuring device. 
   
   
     23. A method as recited in  claim 22 , wherein the optical measuring device is an interferometer. 
   
   
     24. A method as recited in  claim 20 , wherein topographies are measured using a stylus-type device. 
   
   
     25. A method as recited in  claim 20 , wherein the chip is a tape head. 
   
   
     26. A method as recited in  claim 25 , wherein the second surface of the tape head is a substantially flat tape bearing surface. 
   
   
     27. A method as recited in  claim 20 , wherein the relative angle is measured to a factor of tenths of a degree. 
   
   
     28. A method as recited in  claim 20 , wherein the relative angle is measured to a factor of hundredths of a degree. 
   
   
     29. A method as recited in  claim 20 , wherein the relative angle is measured to a factor of thousandths of a degree. 
   
   
     30. A method as recited in  claim 20 , wherein multiple chips are positioned on the receiving surface, wherein the method is consecutively repeated for each of the chips. 
   
   
     31. A method as recited in  claim 20 , wherein multiple chips are positioned on the receiving surface, wherein the method is simultaneously performed on multiple chips. 
   
   
     32. A method as recited in  claim 20 , further comprising determining a flatness of the second surface of the chip. 
   
   
     33. A method for obtaining metrics of a semiconductor chip, comprising:
 positioning a first surface of a chip on an optical flat having a receiving surface; 
 measuring a surface topography of the receiving surface using an optical interferometer; 
 measuring a surface topography of a second surface of the chip using the optical interferometer; and 
 determining a relative angle between the receiving surface and the second surface of the chip using the optical measurements of the receiving surface and the second surface of the chip, wherein the relative angle is measured to a factor of at least tenths of a degree. 
 
   
   
     34. A method as recited in  claim 33 , further comprising determining a flatness of the second surface of the chip. 
   
   
     35. A method as recited in  claim 33 , wherein the chip is a tape head. 
   
   
     36. A method as recited in  claim 35 , wherein the second surface of the tape head is a substantially flat tape bearing surface. 
   
   
     37. A method as recited in  claim 33 , wherein multiple chips are positioned on the optical flat, wherein the method is performed for each of the chips.